In this article, we present the nuclear excitation functions of the fast neutron-induced reactions 52Cr(n,p)52V, 52Cr(n,α)49Ti, 52Cr(n,2n)51Cr, 56Fe(n,p)56Mn, 56Fe(n,α)53Cr, and 56Fe(n,2n)55Fe, because these measurements are critical to estimate the level of the neutron activation for the fusion reactor structural materials. The theoretical computer codes TALYS-1.8 and EMPIRE-3.2.2 have been used for the calculation of the excitation functions. The theoretical calculations consider different nuclear reaction models, level density models and optical model potentials. The calculated excitation function results are compared with the existing experimental data obtained from the IAEA-EXFOR database, as well as with those available in the TENDL-2017 and ENDF/B-VIII.0-evaluated nuclear data libraries. The obtained results show the variation in excitation functions for different level density models. Moreover, we have studied the contribution from different reaction mechanisms in total reaction cross-section which varies with the incident neutron energy. These excitation function results can be useful to estimate the important parameters of nuclear reactors, such as nuclear heating, nuclear transmutation rates, and waste management etc. This kind of information can enhance the basic understanding of the mechanism of the fast neutron-induced nuclear reactions.